INTERACTION OF ACTIVATED EGF RECEPTORS WITH COATED PIT ADAPTINS

The epidermal growth factor (EGF) receptor interacts with plasma membr ane-associated adapter proteins during endocytosis through coated pits . Almost 50 percent of the total pool of alpha-adaptins was coimmunopr ecipitated with the EGF receptor when A-431 cells were treated with EG F at 37-degrees-C, but not at 4-degrees-C. Partial proteolysis of alph a-adaptin suggested that the amino-terminal domain is the region that associates with the EGF receptor. The extent of receptor-adaptin assoc iation was increased in cells depleted of potassium to block endocytos is. These data suggest that receptor-adaptin association occurs in int act cells before coated pits are fully assembled.